The present invention relates to an attachment structure of a camera shutter device for attaching a camera shutter device to a camera body.
FIG. 1 shows a conventional camera shutter device comprising a shutter blade mechanism 1, a shutter mechanism 2 for driving the shutter blade mechanism 1, and a shutter charging mechanism 3 for charging the shutter mechanism 2. The shutter blade mechanism 1 is positioned so as to cover an aperture 5 which is formed on a shutter base 4 for transmitting a light beam to expose a film. As shown in FIG. 1, the shutter mechanism 2 is fixed on the shutter base 4 between the shutter blade mechanism 1 and a sprocket 11 which is positioned so as to guide the film to the right side of a spool 12 for taking up the film. The shutter blade mechanism 1 and the shutter mechanism 2 are attached on a camera body not shown through the shutter base 4.
A charging lever 6 of the shutter charging mechanism 3 is connected through a linkage lever 7 to a charging rotation axis 8 which charges the shutter mechanism 2 when rotated in a clockwise direction in FIG. 1. When charged, the shutter blade mechanism 1 returns to an initial position thereof and a release button not shown comes to be in a state operable to expose the film.
In the conventional camera shutter device mentioned above, the shutter base 4 is fixed by screws on the camera body at the three positions a, b and c as shown in FIG. 1. The end of axis 8 of the shutter mechanism 2, to which the charging lever 6 of the shutter charging mechanism 3 is connected through the linkage lever 7, is fixed on the shutter base 4 for example by a caulked joint.
In the conventional camera shutter device mentioned above, however, since the end of axis 8 is fixed on the shutter base 4, the charging force by the shutter charging mechanism 3 is directly transmitted through the charging rotation axis 8 to the shutter base 4 which is screwed on the camera body at the three positions a, b and c. Therefore, it has a problem that the shutter base 4 is deformed in the plane direction by the charging force. Especially, in a high-speed shutter device, as the charging force of the shutter charging mechanism 3 is strong, the deformation of the shutter base 4 is scaled up, whereby the operation of the shutter blade mechanism 1 is affected so as to deteriorate the shutter performance, and a loss of the charging force is scaled up.
Therefore, to solve these problems, the number of the screws by which the shutter base 4 is fixed to the camera body can be increased so as to prevent the shutter base 4 from being deformed by the charging force of the shutter charging mechanism 3. However, the method to increase the number of screws has a defect that the flatness of the shutter base 4 is affected in a static state and the shutter performance of the shutter blade mechanism 1 is deteriorated as is in the conventional device. So, it is not preferable to adopt the method mentioned above.